Gyroscopic instrument



Aug. 14, 1951 J. P. WATSON 2,563,983

GYROSCOP I C INSTRUMENT Filed April 5, 1949 2 Sheets-Sheet l dames p. Wa fsa/7 Aug- 14, 1951 J. P. WATSON 2,563,983

GYROSCOPIC INSTRUMENT Filed April 5, 1949 2 Sheets-Sheet 2 IN V EN TOR.

dames P. Watson BY Patented Aug. 14, 1951 asias FICE GYR-OSCOPIC INSTRUMENT James P. Watson, San Diego, Calif., assigner to Paul E. Humphrey, San Diego, Calif.

Application April 5, 1949, Serial No. 85,4@9

(Cl. 'i4-45.4)

14 Claims.

This invention relates to gyroscopic instruments and more particularly to improvements in angular rate indicating gyroscopic devices.

ne of the objects of the present invention is to provide an improved angular rate indicating gyroscopic device embodying a novel manner of mounting the gyroscope gimbal and of resiliently restraining movement of the same. Y

VAnother object of this invention resides in the provision of a single degree of freedom gyro- 'scopic device having a spring restrained gimbal and a position sensing element in operative association for measuring, linearly, the rate of turn of the apparatus upon which the gyroscope is mounted.

Another object lies in providing a novel g'yroscopic device of the above character having an improved arrangement of compenents wherein l lthese components when assembled will be accurately located relative to one another, and which accurate relationship is readily attained and maintained.

Another object of the invention is the provision of an improved construction for securing complete hermetic sealing of an angular rate indicating gyroscope device within its housing.

A further object is to provide a novel construction for the gyroscopic device of the above character wherein the housing for the instrument serves as a stationary supporting structure for A still further object is the provision of a housing of the character indicated adapted to support upon its base the assembled components of the gyroscopic device.

Still another object resides in providing a construction for the angular rate indicating gyroscopic device permitting a reduction in the size, weight, and number of components, but retaining durability and ease and inexpensiveness of manufacture, and resulting in a device which operates in effective and efficient manner.

Other objects vand features of the present invention will be readily apparent to those skilled in the art from the following specification and appended drawings wherein is illustrated a preferred form of the invention, and in which:

Figure l is a perspective view of a gyroscope embodying the invention.

Figure 2 is a side View partially in section, of the4 gyroscope contained in its housing.

Figure 3 is an enlarged partial View in section of the housing principally illustrating the gimbal bearing supports.

Figure 4 is another enlarged partial view, which view illustrates the terminal assembly employed and sealing details.

Figure 5 is an end view of the base of the housing having a plate secured thereto on which intelligence appears for determining the location within the housing of the principal axes of the gyroscope.

Figure 6 is a perspective view of the base showing details of a support for the gimbal.

Figure 7 is a perspective view of the terminal block.

Figure 8fis a view in perspective of the spring restraining means provided for the gimbal; and

Figure 9 illustrates the Wiring diagram for the circuit employed by the gyroscope.

Referring nowr with greater particularity to the drawings, the present invention is shown as embodying a gyroscopic instrument indicated generallyl by the numeral I0 which comprises a generally rectangular gimbal frame II and gyro rotor I2 of the electric motor type supported between upwardly extending arms I3 and I4 of gimbal frame II. Gyro rotor I2 is of conventional construction comprising a casing or frame I5 which is rotatably supported by suitable bearings (not shown) on a through shaft I6 the ends of which are xedly mounted in any conventional 'manner to the spaced gimbal arms I3 and I4. The gyro rotor l2 may be spun about its spin axis by means of a suitable conventional motor (not shown) contained within casing I5, which motor includes a permanent magnet eld (not shown) aiiXed to shaft I6 and an armature and v windings assembly (not shown) mounted in suitable manner upon the interior wall of the casing I5 in surrounding relationship to the eld. Electrical power from a suitable scure (not shown) is supplied to the motor through a lead II suitably electrically connected through shaft I6 to the motor windings for eiecting rotation of the armature about the stator; this rotative movement of the armature obviously results in rotative movement of casing I5 because it carries the armature, about its supporting shaft I6.

It is apparent that the spin axis of gyro rotor l2 coincides with the axis of shaft I6. This spin axis is furthermore perpendicular to the agis .of gimbal frame II. A housing I8 is provided ior enclosing the gyroscopic instrument IQ, which housing I8 comprises a cylindrical metallic casing I9, an annular metallic cover plate 2| closely received within one end of the casing I9 for closing this end lof the casing and an annular metallic base member 22 snugly iitted into the opposite end of casing I9 for closing this latter end. It is understood that materials other than metal could be utilized in the manufacture of the housing. Each end of casing I-i is counter-bored to provide annular shoulders 23 and 24. Cover plate 2I is adapted to rest upon shoulder 23 and base member 22 will abut shoulder 24. It is to be noted that the depth of the two counter bores has been limited so that each is less than the height of the cover plate 2| and base member 22. This results in a portion 25 of each of these members projecting a slight distance beyond the rims of the cylindrical casing I9 for a purpose to be described. The cover plate 2l and the base member 22 each has an annular, generally square in cross-section, groove 26 cut into its periphery. Within each of these grooves 26 is tted an annular resilient sealing ring 21. These sealing rings 21 are adapted to be compressed between the interior wall of the casing I9 and the defining walls of the grooves 26 to provide an eiective seal at both ends of the casing I9. As shown in the drawings the casing I 9 is externally threaded at each of its ends, as indicated at 3I and 32. Upon these threaded end portions 3l and 32 are fitted ring members 33 and 34 which act on cover plate 2| and base member 22 to maintain them on casing I9. Ring member 33 is provided with an inwardly directed flange 35 which is adapted to engage the projecting portion 25 of cover plate 2| to apply a clamping pressure to the cover plate 2I to effect a tight engagement with shoulder 23. Ring member 34 is similarly provided with an inwardly directed flange 36 which acts in like manner to engage projecting portion 25 of base member 22 to clamp this member tightly against its associated shoulder 24. This manner of mounting the cover plate 2l and the base member 22 to the casing I9 prevents relative movement between these named elements and results in an effectively rigid construction. As shown the ring member 33 is provided with a second flange 40, outwardly extending from the periphery thereof. This flange 40 is afforded to assist in mounting the device I!! upon an apparatus. It is understood that rings 33 and 34 are interchangeable and either may be threaded upon each end of casing I9.

Gimbal II is suitably mounted within housing I3 for pivotal movement therein about its vertical axis. As shown best in Figure 3 this mounting is provided by the axially spaced bearing assemblies 31 and 38. Bearing assembly 31 is suitably securely mounted upon the annular cover plate 2! and comprises a disc portion 4I from which extends integral cylindrical projection or spindle 42. The longitudinal axis of this spindle i2 is coaxially aligned with the axis of housing I8. A suitable ball bearing assembly 43 is adapted to fit upon stem 42.

The bearing assembly 38 is affixed to base member 22 and comprises, as best shown in Figures 3 and 6, two segment elements 44 and 45 integrally formed on base member 22 with their iiat base portions spaced from and in parallel relationship to one another so as to define therebetween a slot or passage, indicated generally by the numeral 46. A cap member 41 is mounted upon and over the segments 44 and 45 and bridges the slot 46. A plurality of screws 48 rigidly secure the cap member 41 rassembled upon the base member 22. These screws 48 are passed through the cap 41 and segments 44 and 45 to project to the exterior of base member 22 where suitable elastic sealing rings (not shown) and elastic stop nuts 5I are tted onto the projecting stud portions to seal eiectively the stud openings in the base member 22.

Cap member 41 has a downwardly extending flange 52 which is adapted to embrace the segments 44 and 45 conning them to prevent any outward lateral separating movement of such segments. Integral with the upper surface of cap member 41 is an upwardly extending spindle means 53, the axis of which coincides with the axis of housing I8 to place it in coaxial alignment with spindle 42 on cover plate 2I. A ball bearing assembly 54 is adapted to be supported on spindle 53.

Generally rectangular gimbal frame II includes spaced horizontal or transverse arms 55 and 56 interconnecting the opposite ends of upwardly extending arms I3 and I4 and paralleling the spin axis of gyro rotor I2. Centrally of each of the transverse arms 5,5 and 56 is provided an annular recess 51, which recesses 51 are to accommodate the ball bearing assemblies 43 and 54 and receive the opposed spindles 42 and 53, and thereby eiTect the pivotal mounting of gimbal frame II.

Secured to upper transverse arm 55 is a suitable weight 68 for eiecting proper balance of the assembled gimbal frame II and gyro rotor I2.

Rotatably supporting gimbal frame II at its opposite ends by means of the spaced bearing assemblies 31 and 38, xedly and accurately located in cover plate 2I and base member 22, assures that the gimbal frame II is accurately positioned and aligned and further restrains the gimbal frame I I against any tipping action within the casing I8.

With the design provided for the present invention there is no requirement that the gimbal frame I I be adjusted lengthwise or in axial direc*- tion and therefore a possibility of maladjustment of the gimbal within housing I8 is avoided. To avoid the necessity for lengthwise adjustment of gimbal frame I I the annular shoulders 23 and 24 cut into the ends of casing I9 are held to close tolerances. The cover plate 2I and the base member 22, associated with shoulders 23 and 24, will then be located in accurately spaced relationship to present the bearing assemblies 31 and 38 in proper mounting position. Discrepancy in the height of the gimbal frame I I is suitably cared for by providing shims 6I on spindle 42.

Free rotation of gimbal frame II about its vertical axis is yieldably restrained by a resilient means 62 located between the gimbal lower transverse arm 56 and the base member 22. Resilient means 62 comprises an elongated, generally rectangular, resilient at member 63 formed of a suitable material such as spring steel. Flat spring member 63 extends through passage 46 parallel to lower transverse arm 56 of gimbal II and lies disposed within housing I8 with a longitudinal edge thereof down, but with this edge spaced a slight distance above the upper surface of base member 22. To support and maintain the flat spring member 63 in desired position within slot 46 and spaced above the surfaces of the base member 22 there is provided a pair of clamping blocks 64 and 65 which are adapted to fit Within slot 46 and to engage with the central portion of :fiat spring member 63 at the fiat faces thereof which provides free portions of the flat spring terior end of conductor shank 96 is tapped to receive terminal screw |05. Tightening of terminal screw in additionto securing an electrical lead to the shank 96 serves to mountv terminal block 8l to base member 22 and results in a compression of sealing member |04 between the insulating bushing III and the terminal block 8l. The resulting lateral expansion of ring |04 seals shank A96 in base member 22. It is to be noted that member |04 'further acts as a connecting link between terminal block 8'! and bushing |08 to provide continuous insulation of the terminal from end to end,

For attachment of an outside electrical lead to the' conductor element 95 there is provided a terminal screw |66 adapted to be threaded into tapped opening in external end |I`| of conductor element 95.

An insulating cover |98 having the same general shape as terminal block 8'! is adapted to be mounted thereon to cover the open ends of passages 88 for protection of the terminals therein.

Within housing I8 and mounted on base member 22 are an induction coil I III and a condenser HI having electrical association with one another and with the gyro rotor I2, and with one end of condenser |II being groundedv to the base 22 by connecting a convenient lead to screw 'I'I which holds stop l5 to the base. This assembly is provided to serve, in well known manner, as a radio noise suppressor for the gyroscope.

Figure 9 illustrates the electrical circuit for the gyrosc'ope of the present invention. As shown gyro rotor I2 is connected by lead II to induction coil IIB which in turn is connected by lead II 2 'to connector assembly 9B on terminal block '8,1. Assembly 98 serves as the point to which electrical power from a suitable external source (not shown) may be fed. An electrical lead I I 3 serves to connect gyro rotor I2 to grounded connector assembly'SI. As illustrated capacitor III is connected in shunt between leads and H3. f

The-opposite ends of the potentiometer 'resistance winding 82 are secured by electric leads H4 and H5 respectively to connector assemblies 92 and 94. Contact` arm 86, slidably operative o-n potentiometer resistance 82, is connected by a lead IIE to connector vassembly 93.

Having reference now to Figure 6 it is noted that cuts or grooves H8 are provided in base member 22. These cuts I I8 serve as passages for connecting wires H2 and H4 led from induction coil IIB and resistance winding 82 and provide convenient means of leading wires H2 and H4 under the flat spring member 63 without hindering the free movement thereof.

On the exterior surface of base member 22 is secured a plate |2I upon which are provided markings indicated' generally by numeral |22, which serve to indicate the direction of the spin axis of gyro rotor I2 within housing I8, and markings, vindicated generally by numeral |23, which locates the direction of the vertical axis of the gimbal frame II. This marking plate |2| provides a'convenient means for insuring that the gyroscop-ic device of the present invention will be properly located on the apparatus it is required to serve.

With the connection of the present invention into any suitable external indicating "circuit '(not showmpower will be'supplied to the gyro rotor I2A for energization and operation thereof. The rate of displacement of the gyro rotor I2 about an axis perpendicular tothe spin axis of the 'gyro rotor I2 and to the gimbal axis, induced by the movement of the apparatus being served, will be indicated through movement of contact arm 86 on winding 82, contact arm 86 movingV each time gimbal'frame II deilects Therate of displace'- ment of the gyro rotor I2 is proportional to` the deection of the gimbal I I so that the signal provided is a linear indication of the action of the gyroscope, this signal will have an accuracy which renders the device satisfactory for use. Characteristics other than a linear response may be achieved by specially shaped springs but since in most cases the result desired is an indication'directly proportional to the rate of turn or rotation of the apparatus, such as an aircraft being stabilized, a fiat spring member 63, as shown and described, is preferred.

Attention is directed to a desirable feature of the present invention,` which feature is the use of a construction resulting in a hermetically sealed gyroscopic instrument having the operating parts located so as not to be subjected to corroding iniluences or foreign matter. A hermetically sealed device is obtained by utilizing close tting parts and compressible resilient sealing means at each of the various openings to the housing I8. The cover plate 2| and the base member 22 support annular sealing members 21 which are compressed against the interior wall surface of casing IG to seal the ends thereof. The various connector assemblies 90, 9|, 92, 93 and Si! all include annular sealing members |04 which seal the openings 9"! in base member 22.y The various screws provided for holding the cap 41, stops 'i5 and T6, the potentiometer insulating base 83 and the induction coil I ID to the base member 22 all have, as has been described, spuitable annular sealing rings (not shown) and elastic stop nuts applied to their exteriorly projecting ends which act to lseal all stud openings through base member 22 and prevent ingress to the housing I8, or egress at high altitude.

As is apparent from the description herein given of the invention the removable base member 22 acts to support all of the various elements of the gyroscope, the cover plate 2| serving only to mount a bearing, assemblyS'I for the upper part of gimbal frame II. With such an arrangement it is possible to assemblethe various working parts in very accurate relationship to one another. This arrangement also permits the use of a housing I8 which can be made to the smallest possible dimension. The housing |18 affords an accurate, unchanging support for holding the bearing spindles 42 and 53 in alignment.

The novel resilient restrainingspring assembly for the gimbal frame I I utilizing a single at spring 63 permits maximum length vof spring in a minimum size housing. Only a single Support is required for the spring, which support acts to clamp the dat spring solidly at its central portion so that its free ends act as separate cantilever springs. The use of a single spring makes it possible to obtain uniform rate indication in either 'direction of movement of gimbal frame I I.

While certain preferred embodiments of the invention have been speciiically disclosed it is understood that the invention is not limited thereto as many variations will be readily apparent to those skilled in the art and the invention is to be given its broadest possible interpretation within the terms of the following claims.

i9 I @CSIYI i ,1. .In aigyroscopicinstrumenta basegmembena gimbal, means :pivotally .supporting ,said gimbal on said vbase vmemben,agyrofrotor mounted in -saidgimbal for spinning about-an axis perpendicular vto Ythe pivotal axisof the gimbal, resilient .means for yieldably restraining said fpvotally supported gimbal against movement from its neutral'position, .saidmeans comprising an clon- 1g-ated iflatlspring member, means for mounting jsaid'latspringy member .on said base .memberiand adjacentsaid l gimbal, saidmounting rmeans sup,- porting saidfflat spring member atisubsta-ntially the-central portion 1 thereof to provide ffree portions extending on leach side of the mounting Ineans,means provided by:saidgimbaliextending toward said flat Aspring i `member 4for ,engagement therewith on each side of Aits mountingmeansior flexing the rfree portions et the flat spring-'member on movement-of sa-idgimial, and Vposition sensing Vmeans Voperatively associated with said gimbal fwherebyrpivotal"movement of said gimbal from `its-ineutral-position is detected.

*li-Etnea Vgyroscopic instrument, a hermetically sealed#housing-comprising -anppen-ended cylin- V'drical casing, an rannular cover member 1 having an annular Aresilient sealing-member mounted oniits 'periphery for sealing `.one `end Yof said :casing,= and fan-'annular-basel member V.also having` an jannular resilient --sealing member .mounted on its-periphery for-sealingthe opposite end ofthe leasing, a 'pivota-llymounted gimbal .supported -rbetweenX-said cover-:member andzsaid base .memlber,a gyro rotor rotatably mounted in saidigimbal, #resilient means `@for -yieldably restraining saidpivotallymounted gimbal,againstwmovement irom litsl neutral postionfsupport `means for said resilient means forllooating itadjacentsaid gim- "bal,-means for effecting an operative connection between said-gimbal and said resilient means, -f position sensing f-means operatively associated v with f said gimbal whereby.l pivotal movement of saidf gimballf-rom its neutral positionl is detected, fa'IV terminal -b'lock *mounted `on theexteriorfiof said `base gmeniber,n an electrical conductor :member extending through 4an opening in Y the terminal 1"block-and an alignedA opening inA said base mem- `"ber -to -projectinto-the interior of the housing, an'l'insulatingbushing disposed on the 4projecting portion of said conductor member, anda sealingmember closing 1 said opening in the base memben land cooperating with said vterminal fblock andV said insulatingbushing to insulate said conductor member throughout-its length.

B-In;aigyroscopicinstrument, a base member, a-gimbaLfmeans pivotally supporting` said gimbal onisaid-'base memberffor-moven-ient Vabout an. axis Hperpendicular to saidbase member, a` gyro-rotor 1 mounted in said 4gimbal -for spinning Y about an axis1perpendiculartol tlflepivotal` axisof thegimbal,flresilientlmeansfor `yieldably Irestraining said "pivotallysupported gimbal against movement 'from its neutrall position, said means -comprising anfelongated 1iiat springmember positioned ad- Fjacentthe'gimbaI, a pair of projecting lspaced 'means'fprovidediby saidy gimbal extending therelfrom i for operative K engagement with l said at jspring'fmember :ior tiiexing the opposite ends 44thereof on= pivotal `movement, of the gimbal inopgpositedirectionabout its axis, and-position sens- V`ing' means operatively associated with said gimbal whereby pivotal movement of said gimbal from its "neutral'position is detected.

JL-fin a gyroscopiciinstrument, a base member,

al gimbal kframe;means on said base memberpi-vi otallygsupportingsaid gimbal frame for movement about an aXiS perpendicular to ,Said base membena erro-rotor mounted on Said gimbal framegfor Vspinning movement about ,an` axis perpendicularto the axis of said gimbal frame, resilientmeans for `yieldably restraining said gimbal frame against pivotal movement from itsneutral position, said resilient means fcomprising anv integral elongated iiatspring member, means lon said basemember for supporting said atspring member kbetween said base member and said gimbal trame, V:said supporting means mounting said flat spring membersubstantially atthe cen- ;tral ,portion thereof, a pair ofprojecting-` members on said gimbal `frame, spaced ,f -rom one :another and extending toward said atspring member rior engagement with the opposite ends thereof and with thesame flat faceof thespring member, whereby the opposite ends of the'viiat spring member will beseparately'exed `and in the same direction .on pivotal movement of the 'gimbal frame in opposite directions about its axis,` and-.position sensing means operatively associated vwith said gimbalframe whereby pivotal movement ofsaid-,gimbal lframe-from its neutral .position is idetected.

' .5. v:Ina gyroscopic instrument, a base memuber, Ika. gimbalfframe, means onfsaid base mem- Lber;pivotallysupporting saidgimbal frame for .movementeabout an axis perpendicular to said .base member, -a .-gyro-rotor .comprising an enclosed Velectric .-motor, ,mounted on said .gimbal frame for spinning movement about an axis perpendicular to the axis of'saidgimbal'frame, `resilient `lmeans for yieldably restraining said gimba1.:irame againstV pivotal movement from fits Yneutral position, .said resilient means comprising .an integralelongatedilat, spring member, means on saidbase member forsupporting said flat .spring member .between said'- base .member Y and v`said gimbal: frame, .saidsupporting means mount- .ing said. ilat spring member substantially at the 4central portionthereof, a pair of projecting mem- ,.berson,saidigimbal'frame spaced from onev anlo'tl'ienand,extending .toward said-nat. spring mem- -ber for engagementiwith the opposite vends-.there- -of :and with the isame vfflat iface of the `spring :memben whereby the oppositeendsvof the flat .spring member .Will be .separately exedand in the same direction son` pivotal movement of. the gimbal frame in opposite directions about its laxis, and-position.. sensing .means operatively as- `sociated-witli said gimbal frame rwhereby vpivotal movement oflsaid-gimbal frame from its vneutral Aposition is detected;saidposition sensingmeans comprising a potentiometer having a resistance winding supported on said'base member and A,a -cooperating electrical contact arm'v thereforsupported on'said gimbal-"frame,

f6. Ina gyroscopic instrument, an enclosed housing comprising a cylindrical casing, a cover member forclosingone end-'thereof and-abase member for closing the opposite end, a gimbal frame-disposed-within the casing, a bearing assembly mounted on said cover member, a--bear- "ing assembly mounted onsaidrbase memberm axialalignment with therst bearing assembly, said ibearing? as s'errbliesY cooperating to pivotally support said'gimbal -frame therebetween, a gyro- -rotOr-mountedon said gimbalframe for spin- Aning about anaxis perpendicular to `the pivotal axis' of thegimbalframe, resilient means 'for yieldably restraining said gimbal irameagainst movement Afrom itsY neutral position, said means `--corr`1prisi1r1ganfelongated flat spring member,

means for mounting said flat spring member on said base member and adjacent said gimbal frame, said mounting means supporting said flat spring member at substantially the central portion thereof to provide free portions extending on each side of the mounting means, means provided by said gimbal frame extending for engagement with the free portions of the hat spring member on each side of its mounting for exing of these free portions of said flat spring member on pivotal movement of said gimbal frame, and position sensing means operatively associated with said gimbal frame whereby pivotal movement of said gimbal frame from its neutral position is detected.

7. In a gyroscopic instrument, an enclosed housing comprising a cylindrical open-ended casing, an annular cover member for closing one end thereof and an annular base member for closing the opposite end, a gimbal frame disposed within the casing, a bearing assembly mounted on said base member in axial alignment with the first bearing assembly, said bearing assemblies cooperating to support said gimbal frame therebetween for pivotal movement about an axis perpendicular to said base member, a gyro rotor mounted on said gimbal frame for spinning movement about an axis perpendicular to the axis of said gimbal frame,

resilient means for yieldably restraining said c gimbal frame against pivotal movement from its neutral position, said resilient means comprising an integral elongated fiat spring member, means on said l,base member for supporting said flat spring member between said base member and said gimbal frame, said supporting means mounting said hat spring member substantially at the central portion thereof, a pair of projecting members on said gimbal frame, spaced from one another and extending toward said flat spring member for engagement with the opposite ends thereof and with the same nat face of the spring member, whereby the opposite ends of the iiat spring member will :be separately flexed Aand in the same direction on pivotal movement of the `gimbal frame in opposite directions about its axis, and position sensing means operatively associated with said gimbal frame whereby pivotal movement of said gimbal frame from its neutral position is del,

tected.

8. In a gyroscopic instrument, an enclosed housing comprising a cylindrical open-ended casing, an annular cover member for closing one end thereof and an annular base member for closing the opposite end, a gimbal frame disposed within the casing, a bearing assembly comprising a projecting spindle means, mounted on said cover member, a bearing assembly comprising a projecting spindle means, mounted on said base member, which latter spindle means is in axial alignment with the spindle means of the first bearing assembly, said bearing assemblies cooperating to support said gimbal frame therebetween for pivotal movement about an axis perpendicular to said base member, a gyro rotor mounted on said gimbal frame for spinning movement about an axis perpendicular to the axis of said gimbal frame, resilient means for yieldably restraining said gimbal frame against pivotal movement from its neutral position, said resilient means comprising an integral elongated flat spring member, means on said base member for supporting said at spring member between said base member and said gimbal frame,

gli

said supporting means mounting said flat spring memlber substantially at the central portion thereof, a pair of projecting members on said gimbal frame, spaced from one another and extending toward said flat spring member for engagement with the opposite ends thereof and with the same flat face of the spring member, whereby the opposite ends of the flat spring member will be separately fiexed and in the same direction on pivotal movement of the gimbal frame in opposite directions about its axis, and position sensing means operatively associated with said gimbal frame whereby pivotal movement of said gimbal frame from its neutral position is detected, said position sensing means comprising a potentiometer having a resistance winding supported on said base member and a cooperating electrical contact arm therefor supported on said gimbal frame.

9. In a gyroscopic instrument, an enclosed housing comprising a cylindrical casing, a cover member for closing one end thereof and a base member for closing the opposite end, a gimbal frame disposed within the casing, a bearing assembly mounted on said cover member, a bearing assembly mounted on said base member in axial alignment with the rst bearing assembly, said bearing assemblies cooperating to pivotally support said gimbal frame therebetween, a gyro rotor mounted on said gimbal frame for spinning about an axis perpendicular to the pivotal axis of the gimbal frame, resilient means for yieldably restraining said gimbal frame against movement from its neutral position, said means comprising an elongated flat spring member, said bearing assembly mounted on said base member having a passage provided therethrough, clamping means located within said passage for mounting said flat spring member between said gimbal frame and said base member, said clamping means supporting said at spring member at substantially the central portion thereof to provide free portions extending on each side of the bearing assembly on the base member, means provided by said gimbal frame extending for engagement with said flat spring member, engaging the free portions thereof on each side of its mounting for exing of these free portions of the flat spring member on pivotal movement of said gimbal frame, and position sensing means operatively associated with said gimbal frame whereby pivotal movement of said gimbal frame from its neutral position is detected.

l0. In a gyroscopic instrument, a hermetically sealed housing comprising an open-ended cylindrical casing, an annular cover member having an annular resilient member mounted on its periphery for sealing one end of said casing, and an annular base member also having an annular resilient sealing member mounted on its periphery for sealing the opposite end of the casing, a gimbal frame disposed within the casing, a bearing assembly mounted on said cover member, a bearing assembly mounted on said base member in axial alignment with the first bearing assembly, said bearing assemblies cooperating to pivotally support said gimbal frame therebetween, a gyro rotor mounted on said gimbal frame for spinning about an axis perpendicular to the pivotal axis of the gimbal frame, resilient means for yieldably restraining said gimbal frame against movement from its neutral position, said means comprising an elongated flat spring member, means for mounting saidr at ,5" l mit jew@ spring member 'on' saidl base member and adiatending ,for engagement with saidiiat spring ',Iiie'mbe'r, engaging the freeportions thereoi on achjsideuoi its mountingfior `ilexing of' thse free `portions or the flat spring member on pivotal movement of said gimbal frame, and position sensing means operatively associated with said gimbal frame whereby `pivotal movement of said gimbal frame from its neutral position is detected.

ll. In a gyroscopic instrument, a hermetically sealed housing comprising an open-ended cylindrical casing, an annular cover member having an annular resilient sealing member mounted in its periphery for sealing one end of said casing, and an annular base member also having an annular resilient sealing member on its periphery for sealing the opposite end of the casing, a gimbal frame disposed within the casing, a bearing assembly mounted on said cover member, a bearing assembly mounted on said base member in axial alignment with the rst bearing assembly, said bearing assemblies cooperating to support said gimbal frame v therebetween for pivotal movement about an axis perpendicular to said i base member, a gyro-rotor mounted on said gimbal frame for spinning movement about an axis perpendicular to the axis of said gimbal frame, resilient means for yieldably restraining said gimbal frame against pivotal movement from its neutral position, said resilient means comprising an integral elongated flat spring member, means on said base member for supporting said flat spring member between said base member and said gimbal frame, said supporting means mounting said nat spring member substantially at the central portion thereof, a pair of projecting members on said gimbal frame, spaced from one another and extending toward said flat spring member for engagement with the opposite ends thereof and with the same flat face of the spring member, whereby the opposite ends of the at spring member will be separately flexed and in the same direction on pivotal movement of the gimbal frame in opposite directions about its axis, and position sensing means operatively associated with said gimbal frame whereby pivotal movement of said gimbal frame from its neutral position is detected.

12. In a gyroscopic instrument, a hermetically sealed housing comprising an open-ended cylindrical casing, an annular cover member having an annular resilient sealing member mounted in its periphery for sealing one end of said casing, and an annular base member also having an annular resilient sealing member on its periphery for sealing the opposite end of the casing, spaced annular shoulders formed at each end of said casing engageable by said cover member and said base member for locating said members relative to one another, a gimbal frame disposed within the casing, a iirst bearing assembly comprising a projecting spindle means, mounted on said cover member, a second bearing assembly comprising a projecting spindle means, mounted on said base member, which latter spindle means is in axial alignment with the spindle means of said first bearing assembly, said bearing assemblies cooperating to support said gimbal frame therebetween for pivotal movement about an axis persemifinal tessile page mente i', a gfyroe'rtbr comprising "an 'electric frotr mounted `on vsaid Vgimbal iranre 'for spinriirig inov'eme'rit about an p i o t e Iaxis of fsaid gimbal u "'resllrent tine ns Yfor3yie'ldab'ly '1"estr'alining l`sai gimbal-frameagainstpivtal'movement f5 `its 'neutral position, `said v'nfa'ns rompi ng elongated'fat 'ispriii'gmeiiberf said bearing sembly mounted on said base member having a passage provided therethrough, clamping means located within said passage for mounting said flat spring member between said gimbal frame and said base member, said clamping means supporting said flat spring member at substantially the central portion thereof to provide free portions extending on each side of the bearing assembly on the base member, a pair of projecting members on said gimbal frame, spaced from one another and extending toward said flat spring member for engagement with the opposite ends thereof and with the same flat face of the spring member, whereby the opposite ends of the flat spring member will be separately exed and in the same direction on pivotal movement of the gimbal frame in opposite directions about its axis, and position sensing means operatively associated with said gimbal frame whereby ipivotal movement of said gimbal frame from its neutral position is detected, said position sensing means comprising a potentiometer having a resistance Winding supported on said base member and a cooperating electrical contact arm therefor supported on said gimbal frame.

13. In a gyroscopic instrument, an enclosed housing comprising a cover member, a base member, a gimbal, means pivotally supporting said gimbal on said base member for movement about an axis perpendicular thereto, a gyro-rotor mounted in said gimbal for spinning about an axis perpendicular to the pivotal axis of the gimbal, resilient means for yieldably restraining said pivotally supported gimbal against movement from its neutral position, said means comprising an elongated flat spring member positioned adjacent the gimbal, means provided by said gimbal extending in the direction of the flat spring member and adapted to engage said flat spring member for flexing thereof on movement of said gimbal, position sensing means operatively associated with said gimbal whereby pivotal movement of said gimbal from its neutral position is detected, and means provided on the exterior of said base member for indicating the direction of the spin axis of gyro-rotor and the location of the pivotal axis of said gimbal frame.

14. In a gyroscopic instrument, a hermetically sealed housing comprising an open-ended cylindrical casing, an annular cover member having an annular resilient sealing member mounted on its periphery for sealing one end of said casing, and an annular base member also having an annular resilient sealing member mounted on its periphery for sealing the opposite end of the casing, a gimbal, means for pivotally mounting said gimbal for pivotal movement about an axis perpendicular to said base member, a gyro-rotor mounted in said gimbal for spinning about an axis perpendicular to the pivotal axis of the gimbal, resilient means for yieldably restraining said pivotally supported gimbal against movement from its neutral position, said means comprising an elongated flat spring member positioned adjacent the gimbal, means provided by said gimbal extending in the direction of the fiat spring member and adapted to engage said ilat spring member for flexing thereof en movement of said gimbal, position sensing means operatively associated with said gimbal whereby pivotal movement of said gimbal from its neutral position is detected, and means provided on the exterior of said base member for indicating the direction of the spin axis of gyro-rotor and the location of the pivotal axis of said gimbal frame.

JAMES P. WATSON.

16 REFERENCES CITED The following references are of record in the file of this patent: 

